What is drug antagonism?

Drug antagonism refers to the interaction between two drugs that results in a decrease in their overall effectiveness. This occurs when one drug counteracts or inhibits the effects of another, leading to a diminished therapeutic response. Understanding this concept is essential in pharmacology since it can influence treatment outcomes, especially when administering multiple medications.

In contrast, the other choices address different aspects of drug interactions that do not encapsulate the definition of antagonism. For example, the idea of drugs enhancing each other's effects relates to synergy or potentiation, while positive interactions without side effects could refer to neutral or beneficial drug combinations. The notion of ineffectiveness due to overuse pertains to concepts such as drug tolerance or dependence, which are unrelated to the direct interaction mechanisms described by antagonism.